Instances 
Instances
Definition
An R/3 instance is defined when the R/3 System is installed.
In the R/3 System, the term "instance" is often used as a synonym for "server" or "application server". This depends on the chosen installation environment. It is possible to install several instances on a single application server.
An R/3 instance defines a group of resources such as memory, work processes etc., usually in support of a single application server or database server within an R/3 client/server environment. Application servers share a common set of buffers, and are controlled by the same dispatcher process.
An instance is the mechanism to which users connect to work in the R/3 system, and is managed by the CCMS as one single entity.
An R/3 System can consist of one or more instances. For example, an R/3 System with a single instance containing only a central server, or a client/server system containing two or more separate instances.
For each R/3 instance:
An R/3 instance is not assigned automatically to an operation mode.
See also:
Assigning an Instance Definition to an Operation Mode Creating the Instance Definition for all Servers Prerequisites for Starting Remote Instances Creating the Instance Definition for one Server Assigning an Instance Definition Manually Consistency Check Starting and Stopping Instances Setting Up the CCMS Monitoring Servers and Work Processes